Wood pulp grinder



sept.' 29, 1942. R. STEHR 2,297,438

' WOOD PULP GRINDER Filed Nov. l0, 1939 2 Sheets-Sheet 1 .7m/enfer.;

Sept. 29, 1942. R. sTEHR WOOD PULP GRINDER Filed Nov. y1o, 1959 2 Sheets-Sheetl 2l Patented Sept. 29, 1942 srs'rs ears OFFICE.

WOOD PULP GRINDER Robert Stehr, Gorlitz, Germany; vested in the Alien Property Custodian 1 Claim.

Wood grinding machines which operate continually are known, in which the wood gripped on the circumference or on the end faces is continually fed to the grinding stone.

As the efficiency of the grinding increases with the size of the grinding surface, this grinding surface has been made as large as possible. In the machines of known construction a wide wood shaft is therefore generally arranged above the grinding stone.

Wide wood staples possess, however, the inconvenience that the woods in the middle of the staple are not gripped with suicient security. so that the wood shaft must be built extraordinarily high in order to attain a suiiicient pressing of the woods against the grinding stone.

In wide wood staples, that is with long grinding faces, serious difficulties are caused by the discharging of the heat produced between wood and stone so that often extraordinarily high temperatures occur whereby the quality of the wood pulp is unfavourably influenced.

All these inconveniences are overcome according to the invention in that in wood grinding machines, in which the wood staple is gripped on the longitudinal or end sides and continually fed to the grinding stone, the wood staple is subdivided into several separate staples, moved towards the grinding stone with a similar speed, so that the subdividing elements are on both sides in contact with the wood and are either moved at the same speed as the wood, for instance in the form of vertical wood trunks, towards the grinding stone and ground by the same o1` constructed as feeding devices, for instance conveyf ing spindles.

According to the invention the subdividing means serving as conveying devices may be mounted, singly or all together adjustable within the wood staple, directly above the grinding surface of the grinding stone or freely oscillating above this surface and tapered towards the lower end.

By the invention, by which also in continual grinding machines a sufficient gripping of the Wood shaft may be made much lower than in the known continuous grinder, so that saving in material and in expenses for building are obtained and at the same time the efficiency is increased.

Several embodiments of the invention are shown in side elevation in the accompanying drawings in which Fig. 1 shows a form of construction, in which for the subdivision of the wide wood staple into several individual staples f moved at similar speed towards the grinding stone .d upright wood trunks a are provided which are charged together with the wood for grinding, moved towards the grinding stone d and ground by the same. In order to obtain a secure conveying of the wood to be ground, stapled on either side of the wood trunks a, these trunks may have notches g or the like.

Figs. 2 and 3 show other forms of construction in which for the subdivision of the wood staples, conveying means such as conveying spindles b are providedwhich preferably are mounted directly above the grinding surface of the grinding stone d or may be arranged freely oscillatable and which may taper towards the lower end. As in the conveying means arranged within the wood staple the woods f are stapled at either side of the same and therefore relieve the conveying arrangements, these can be of less great dimension than those which are on the outer sides.

e designates spraying tubes arranged underneath the conveying spindles b and destined to spray water, solvent for resin and the like upon the grinding stone d. Plates c may be placed against the grinding stone for reducing the amount of splinters.

Iclaim:

In a wood grinder wherein the wood staple is gripped on the long or end sides and continually fed to a grinding stone, said wood grinder comprising a grinding stone and an especially wide wood shaft above the grinding stone, continuously operating feeding means at opposite sides of the wood shaft, dividing means for subdividing said wood shaft into at least two tightly juxtaposed wood feeding compartments arranged in the wide shaft, and said dividing means comprising rotatable shafts provided with feed means on their circumferences, the axis of each of said shafts orientated substantially radially with respect to the grinding stone so as to feed material on their opposite sides toward the grinding stone.

ROBERT STEI-IR. 

